Measuring complexity for building projects : a Delphi study

Purpose---The aim of this study is to identify complexity measures for building projects in the People’s Republic of China (PRC). Design/Methodology/Approach---A three-round of Delphi questionnaire survey was conducted to identify the key parameters that measure the degree of project complexity. A complexity index (CI) was developed based on the identified measures and their relative importance. Findings---Six key measures of project complexity have been identified, which include, namely (1) building structure & function; (2) construction method; (3) the urgency of the project schedule; (4) project size/scale; (5) geological condition; and (6) neighboring environment. Practical implications---These complexity measures help stakeholders assess degrees of project complexity and better manage the potential risks that might be induced to different levels of project complexity. Originality/Value---The findings provide insightful perspectives to define and understand project complexity. For stakeholders, understanding and addressing the complexity help to improve project planning and implementation.

Identification of selection criteria for operational variations of the design-build system : a delphi study in China

The design-build (DB) system has been demonstrated as an effective delivery method and has gained popularity worldwide. However it is observed that a number of operational variations of DB system have emerged since the last decade to cater for different client’s requirements. After the client decides to procure his project through the DB system, he still has to choose an appropriate configuration to deliver their projects optimally. However, there is little research on the selection of DB operational variations. One of the main reasons for this is the lack of evaluation criteria for determining the appropriateness of each operational variation. To obtain such criteria, a three-round Delphi survey has been conducted with 20 construction experts in the People’s Republic of China (PRC). Seven top selection criteria were identified. These are: (1) availability of competent design-builders; (2) client’s capabilities; (3) project complexity; (4) client’s control of project; (5) early commencement & short duration; (6) reduced responsibility or involvement; and (7) clearly defined end user’s requirements. These selection criteria were found to have a statistically significant agreement. These findings may furnish various stakeholders, DB clients in particular, with better insight to understand and compare the different operational variations of the DB system.

Developing a fuzzy multi-criteria decision-making model for selecting design-build operational variations

Many academic researchers have conducted studies on the selection of design-build (DB) delivery method; however, there are few studies on the selection of DB operational variations, which poses challenges to many clients. The selection of DB operational variation is a multi-criteria decision making process that requires clients to objectively evaluate the performance of each DB operational variation with reference to the selection criteria. This evaluation process is often characterized by subjectivity and uncertainty. In order to resolve this deficiency, the current investigation aimed to establish a fuzzy multicriteria decision-making (FMCDM) model for selecting the most suitable DB operational variation. A three-round Delphi questionnaire survey was conducted to identify the selection criteria and their relative importance. A fuzzy set theory approach, namely the modified horizontal approach with the bisector error method, was applied to establish the fuzzy membership functions, which enables clients to perform quantitative calculations on the performance of each DB operational variation. The FMCDM was developed using the weighted mean method to aggregate the overall performance of DB operational variations with regard to the selection criteria. The proposed FMCDM model enables clients to perform quantitative calculations in a fuzzy decision-making environment and provides a useful tool to cope with different project attributes.

Key competences of design-build clients in China

Purpose-- DB clients play a vital role in the delivery of DB system and the clients’ competences are critical to the success of DB projects. Most of DB clients, however, remain inexperienced with the DB system. This study, therefore, aims to identify the key competences that DB clients should possess to ensure the success of DB projects in the construction market of China. Design/Methodology/Approach -- Five semi-structured face-to-face interviews and two rounds Delphi questionnaire survey were conducted in the construction market of China to identify the key competences of DB clients. Rankings have been assigned to these key competences on the basis of their relative importance. Findings-- Six ranked key competences of DB clients have been identified, which are, namely, (1) the ability to clearly define project scope and objectives; (2) financial capacity for the projects; (3) capacity in contract management; (4) adequate staff or consulting team; (5) effective coordination with DB contractors and (6) experience with similar design-build projects. Calculation of Kendall’s Coefficient of Concordance (W) indicates a statistically significant consensus of panel experts on these top six key competences. Practical implications—Clients should clearly understand the competence requirements in DB projects and should assess their DB capability before going for the DB option. Originality/Value-- The examination of DB client’s key competences will help the client deepen the understanding of the DB system. DB clients can also make use of the research findings as guidelines to improve their DB competence.

Identification of key competences of design-builders in the construction market of the People’s Republic of China (PRC)

Design-builders play a vital role in the success of DB projects. In the construction market of the People’s Republic of China, most of the design-builders, however, lack adequate competences to conduct the DB projects successfully. The objective of this study is, therefore, to identify the key competences that design-builders should possess to not only ensure the success of DB projects but also acquire the competitive advantages in the DB market. Five semi-structured face-to-face interviews and two rounds of Delphi questionnaire survey were conducted to identify the key competences of design-builders. Rankings have been assigned to these key competences on the basis of their relative importance. Six ranked key competences of design-builders have been identified, which are, namely, (1) experience with similar DB projects; (2) capability of corporate management; (3) combination of building techniques and design expertise; (4) financial capability for DB projects; (5) enterprise qualification and scale; and (6) credit records and reputation in the industry. The design-builders can make use of the research findings as guidelines to improve their DB competence. These research findings will also be useful to clients during the selection of design-builders.

Review of the design-build market in the People’s Republic of China

Design-build (DB) system has been demonstrated as an effective delivery method and been widely used overseas. However it does not receive the same popularity in the People’s Republic of China (PRC). This paper first conducts a literature review on advantages and disadvantages of DB in general; then it gives an overview of the PRC construction industry. There are ample evidences that the DB system will theoretically bring benefits to the PRC construction industry. After a thorough investigation of the current DB market, it can be concluded that the development of the DB system is still at its infancy stage. The barriers to entry have been finally identified, which relate to the legal restraints, negative owner attitude, and high requirement of DB projects. These barriers constitute obstacles to the development of DB system in the PRC. However, with rapid growth of construction industry, new requirements in modern construction projects, and strong promotion from governments, it is believed that the domestic DB market will have great potential in the near future.

The investigation of design-build variants in the construction market of the People’s Republic of China

Design-Build (DB) system has been widely adopted overseas but it has not received the same popularity yet in the People’s Republic of China. The selection of design-build variant is regarded as one of the critical obstacles to the application of this alternative. This paper investigates categories of design-build variants in the construction market of China. The develop-and-construction, enhanced design-build, traditional-design-build and engineering procurement-construction (EPC) are the four current designbuild variants adopted by clients. Each of them is developed to meet a varying set of circumstances and has its own advantages and disadvantages. The develop-and-construction is mostly used in large, complex projects in housing industry and it will guarantee client’s great control over the project while still leave some design room for the contractor. The traditional-design-build and enhanced-design-build systems are mostly applied in projects that are comparatively simple, small-scale, and the DB contractors will have greater control of the projects. The EPC is the extension of pure design-build method and is widely adopted in the petrochemical, metallurgical and electronic fields because of the high-technique requirements and the necessity for one entity to control the design, construction, procurement and commissioning etc. Four corresponding design-build projects are also presented in this paper in order to better illustrate the operational process and provide the insight for understanding the design-build variants in Mainland China.

Identification of key competences of DB clients in the construction market of China

The design-build system has been demonstrated as an effective delivery method and gained popularity worldwide. Although there are an increasing number of clients adopting DB method in China, most of them remain inexperienced with method. The objective of this study is therefore to identify the key competences that a client or its consultant should possess to ensure the success of DB projects. Face-to-face interviews and a two-round Delphi questionnaire survey were conducted to find the following six key competences of clients, which include the (1) ability to clearly articulate project scope and objectives; (2) financial capacity for DB projects; (3) capability in contract management; (4) adequate staff or consulting team; (5) effective coordination with contractors and (6) experience with similar DB projects. This study will hopefully provide clients with measures to evaluate their DB competence and further promote their understanding of DB system in the PRC.

Investigation of barriers to entry into the design-build market in the People’s Republic of China (PRC)

Although the design-build (DB) system has been demonstrated to be an effective delivery method and has gained popularity worldwide, it has not gained the same popularity in the construction market of China. The objective of this study was, theretofore, to investigate the barriers to entry in the DB market. A total of 22 entry barriers were first identified through an open-ended questionnaire survey with 15 top construction professionals in the construction market of China. A broad questionnaire survey was further conducted to prioritize these entry barriers. Statistical analysis of responses shows that the most dominant barriers to entry into the DB market are, namely, lack of design expertise, lack of interest from owners, lack of suitable organization structure, lack of DB specialists, and lack of credit record system. Analysis of variance indicates that there is no difference of opinions among the respondent groups of academia, government departments, state-owned company, and private company, at the 5% significance level, on most of the barriers to entry. Finally, the underlying dimensions of barriers to entry in the DB market were investigated through factor analysis. The results indicate that there are six major underlying dimensions of entry barriers in DB market, which include, namely, the competence of design-builders, difficulty in project procurement, characteristics of DB projects, lack of support from public sectors, the competence of DB owners, and the immaturity of DB market. These findings are useful for both potential and incumbent design-builders to understand and analyze the DB market in China.

Response of a plastic pipe buried in expansive clay

Failure of buried pipes due to reactive soil movement (e.g. shrinking/swelling) is a common problem for water and gas pipe networks in Australia and the world. Soil movement is closely related to seasonal climatic change, and particularly to the moisture content of soil. Although some research has been carried out to understand the effect of freezing and thawing of soils and temperature effects in colder climates, very limited research has been undertaken to examine the possible failure mechanisms of pipes buried in reactive soils. This study reports the responses of a 2 m long polyethylene pipe buried in reactive clay in a box under laboratory conditions. The soil and pipe movements were measured as the soil was wetted from the bottom of the box. It was observed that the pipe underwent substantial deformation as the soil swelled with increase of the moisture content. The results are explained with a simplified numerical analysis.

A study on the use of acoustic emission technique as a structural health monitoring tool

As civil infrastructures such as bridges age, there is a concern for safety and a need for cost-effective and reliable monitoring tool. Different diagnostic techniques are available nowadays for structural health monitoring (SHM) of bridges. Acoustic emission is one such technique with potential of predicting failure. The phenomenon of rapid release of energy within a material by crack initiation or growth in form of stress waves is known as acoustic emission (AE). AEtechnique involves recording the stress waves bymeans of sensors and subsequent analysis of the recorded signals,which then convey information about the nature of the source. AE can be used as a local SHM technique to monitor specific regions with visible presence of cracks or crack prone areas such as welded regions and joints with bolted connection or as a global technique to monitor the whole structure. Strength of AE technique lies in its ability to detect active crack activity, thus helping in prioritising maintenance work by helping focus on active cracks rather than dormant cracks. In spite of being a promising tool, some challenges do still exist behind the successful application of AE technique. One is the generation of large amount of data during the testing; hence an effective data analysis and management is necessary, especially for long term monitoring uses. Complications also arise as a number of spurious sources can giveAEsignals, therefore, different source discrimination strategies are necessary to identify genuine signals from spurious ones. Another major challenge is the quantification of damage level by appropriate analysis of data. Intensity analysis using severity and historic indices as well as b-value analysis are some important methods and will be discussed and applied for analysis of laboratory experimental data in this paper.

Interaction of myxomatosis and Rabbit Haemorrhagic Disease in wild rabbit

Increasing resistance of rabbits to myxomatosis in Australia has led to the exploration of Rabbit Haemorrhagic Disease, also called Rabbit Calicivirus Disease (RCD) as a possible control agent. While the initial spread of RCD in Australia resulted in widespread rabbit mortality in affected areas, the possible population dynamic effects of RCD and myxomatosis operating within the same system have not been properly explored. Here we present early mathematical modelling examining the interaction between the two diseases. In this study we use a deterministic compartment model, based on the classical SIR model in infectious disease modelling. We consider, here, only a single strain of myxomatosis and RCD and neglect latent periods. We also include logistic population growth, with the inclusion of seasonal birth rates. We assume there is no cross-immunity due to either disease. The mathematical model allows for the possibility of both diseases to be simultaneously present in an individual, although results are also presented for the case where co infection is not possible, since co-infection is thought to be rare and questions exist as to whether it can occur. The simulation results of this investigation show that it is a crucial issue and should be part of future field studies. A single simultaneous outbreak of RCD and myxomatosis was simulated, while ignoring natural births and deaths, appropriate for a short timescale of 20 days. Simultaneous outbreaks may be more common in Queensland. For the case where co-infection is not possible we find that the simultaneous presence of myxomatosis in the population suppresses the prevalence of RCD, compared to an outbreak of RCD with no outbreak of myxomatosis, and thus leads to a less effective control of the population. The reason for this is that infection with myxomatosis removes potentially susceptible rabbits from the possibility of infection with RCD (like a vaccination effect). We found that the reduction in the maximum prevalence of RCD was approximately 30% for an initial prevalence of 20% of myxomatosis, for the case where there was no simultaneous outbreak of myxomatosis, but the peak prevalence was only 15% when there was a simultaneous outbreak of myxomatosis. However, this maximum reduction will depend on other parameter values chosen. When co-infection is allowed then this suppression effect does occur but to a lesser degree. This is because the rabbits infected with both diseases reduces the prevalence of myxomatosis. We also simulated multiple outbreaks over a longer timescale of 10 years, including natural population growth rates, with seasonal birth rates and density dependent(logistic) death rates. This shows how both diseases interact with each other and with population growth. Here we obtain sustained outbreaks occurring approximately every two years for the case of a simultaneous outbreak of both diseases but without simultaneous co-infection, with the prevalence varying from 0.1 to 0.5. Without myxomatosis present then the simulation predicts RCD dies out quickly without further introduction from elsewhere. With the possibility of simultaneous co-infection of rabbits, sustained outbreaks are possible but then the outbreaks are less severe and more frequent (approximately yearly). While further model development is needed, our work to date suggests that: 1) the diseases are likely to interact via their impacts on rabbit abundance levels, and 2) introduction of RCD can suppress myxomatosis prevalence. We recommend that further modelling in conjunction with field studies be carried out to further investigate how these two diseases interact in the population.

A systematic review : the effects of orientation programs for cancer patients and their family/carers

Objectives To assess the effects of information interventions which orient patients and their carers/family to a cancer care facility and the services available within the facility. Design Systematic review of randomised controlled trials (RCTs), cluster RCTs and quasi-RCTs. Data sources MEDLINE, CINAHL, PsycINFO, EMBASE and the Cochrane Central Register of Controlled Trials. Methods We included studies evaluating the effect of an orientation intervention, compared with a control group which received usual care, or with trials comparing one orientation intervention with another orientation intervention. Results Four RCTs of 610 participants met the criteria for inclusion. Findings from two RCTs demonstrated significant benefits of the orientation intervention in relation to reduced levels of distress (mean difference (MD): −8.96, 95% confidence interval (95%CI): −11.79 to −6.13), but non-significant benefits in relation to the levels state anxiety levels (MD −9.77) (95%CI: −24.96 to 5.41). There are insufficient data on the other outcomes of interest. Conclusions This review has demonstrated the feasibility and some potential benefits of orientation interventions. There was a low level of evidence to suggest that orientation interventions can reduce distress in patients. However, other outcomes, including patient knowledge recall/satisfaction, remain inconclusive. The majority of trials were subjected to high risk of bias and were likely to be insufficiently powered. Further well conducted and powered RCTs are required to provide evidence for determining the most appropriate intensity, nature, mode and resources for such interventions. Patient and carer-focused outcomes should be included.

Rethinking prefabricated construction management using the VP-based IKEA model in Hong Kong

Prefabricated construction is regarded by many as an effective and efficient approach to improving construction processes and productivity, ensuring construction quality and reducing time and cost in the construction industry. However, many problems occur with this approach in practice, including higher risk levels and cost or time overruns. In order to solve such problems, it is proposed that the IKEA model of the manufacturing industry and VP technology are introduced into a prefabricated construction process. The concept of the IKEA model is identified in detail and VP technology is briefly introduced. In conjunction with VP technology, the applications of the IKEA model are presented in detail, i.e. design optimization, production optimization and installation optimization. Furthermore, through a case study of a prefabricated hotel project in Hong Kong, it is shown that the VP-based IKEA model can improve the efficiency and safety of prefabricated construction as well as reducing cost and time.

The use of virtual prototyping for hazard identification in the early design stage

Purpose: The construction industry is well known for its high accident rate and many practitioners consider a preventative approach to be the most important means of bringing about improvements. This paper addresses previous research and the weaknesses of existing preventative approaches and a new application is described and illustrated involving the use of a multi-dimensional simulation tool - Construction Virtual Prototyping (CVP). Methodology: A literature review was conducted to investigate previous studies of hazard identification and safety management and to develop the new approach. Due to weaknesses in current practice, the research study explored the use of computer simulation techniques to create virtual environments where users can explore and identify construction hazards. Specifically, virtual prototyping technology was deployed to develop typical construction scenarios in which unsafe or hazardous incidents occur. In a case study, the users’ performance was evaluated their responses to incidents within the virtual environment and the effectiveness of the computer simulation system established though interviews with the safety project management team. Findings: The opinions and suggestions provided by the interviewees led to the initial conclusion that the simulation tool was useful in assisting the safety management team’s hazard identification process during the early design stage. Originality: The research introduces an innovative method to support the management teams’ reviews of construction site safety. The system utilises three-dimensional modelling and four-dimensional simulation of worker behaviour, a configuration that has previously not been employed in construction simulations. An illustration of the method’s use is also provided, together with a consideration of its strengths and weaknesses.